Human health is negatively impacted by many microbial entities. Inoculation by fungi and bacteria can cause a wide variety of sicknesses and ailments. It is well known that the washing of hard surfaces, food (e.g. fruit or vegetables) and skin, especially the hands, with antimicrobial or non-medicated soap, can remove many fungi and bacteria from the these surfaces, thereby reducing the chances of fungi or bacterial inoculation. Removal of the fungi and bacteria is due to the surfactants within the soap and the mechanical action of the wash procedure. For this reason, it is recommended that people wash frequently to reduce the spread of fungi and bacteria.
Antibacterial cleansing products have been marketed in a variety of forms, including antibacterial soaps, hard surface cleaners, and surgical disinfectants. Rinse-off antimicrobial soaps have been formulated to provide bacteria removal during washing. Such conventional antibacterial cleansing products have been shown to also provide a residual effectiveness against some common gram-positive bacteria. Active antimicrobial agents are deposited during washing onto the cleansed surface and residual active ingredients control the viability and growth of some surviving and some newly contacted transient bacteria. For example, antibacterial soap, when used regularly in hand washing, has been found to provide a 90% to 97% reduction in gram-positive bacteria after two to five hours. Unfortunately, some topical antibacterial agents such as pyrithiones, thiazolones, sulfites, diazo compounds, chlorinated organics, brominated organics, phenols, bisphenols, resourcinols, and alkylated parabens have been linked to antibiotic resistant bacteria.
Many cleansing formulations that are currently available in the marketplace are nonabrasive “waterless” skin cleansers, meaning water does not have to be added during the hand cleansing process. The waterless cleansers currently commercially available typically use both polar and nonpolar ingredients, and have a gelatinous or paste-like, high viscosity consistency. The gelatinous consistency of the cleanser has been essential in such waterless hand cleansers to achieve the continuous cleansing action, due to extended contact between the cleanser and the skin. If the cleanser were liquid instead of gel, the cleanser would not adequately bind to the skin and provide continuous cleansing. The lower viscosity of a liquid cleanser can also cause the cleanser to run off of the hands, thereby facilitating the potential waste of cleanser. Therefore, waterless skin cleaners use a gelatinous or highly viscous consistency. These hand cleanser formulations also typically contain one or more antibacterial compounds to provide resistance to bacterial buildup and a degree of hand “sanitization” when they are used. Antimicrobial liquid cleansers are disclosed in U.S. Pat. No. 4,847,072, Bissett et al, issued Jul. 11, 1989; U.S. Pat. No. 4,939,284, Degenhardt, issued Jul. 3, 1990; and U.S. Pat. No. 4,820,698, Degenhardt, issued Apr. 11, 1989).
Ethanol and/or Isopropyl alcohol-based compositions require at least 60% percent volume/volume (v/v) (approximately 52% by weight to volume (wt/v)) to be useful for antibacterial or disinfecting purposes. Further, due to the disinfecting characteristics of alcohol, it is perceived that the higher the content the better the product.
Industrial and hand cleansing formulations typically contain a surfactant that solubilizes or emulsifies the oils, debris, and soil present on a substrate. These formulations inherently have oil-cleansing limitations when oil-emulsifiability or solvency alone is used as a cleaning mechanism. The alcohol-based disinfectant solutions are thickened, typically with use paraffin, lanolin or waxes, to eliminate the waste and facilitate spreading. However, use of thickened gels leaves a tacky feeling on the skin that builds up after repetitive use, making it necessary to wash off the thickeners before continuing the usage of an alcohol antiseptic solution.
Cleansers with high alcohol content are useful to disinfect, but require alcohol levels of at least 60%. According to Klausner, in U.S. Pat. No. 3,131,153, if more than 64% alcohol is used then a non-homogeneous compositions is obtained. A non-irritant skin disinfecting high alcohol content formulation for use as a skin-washing agent was attained by combining emulsifiers, surfactants and skin emollients to be used as a gel or ointment as described in U.S. Pat. No. 5,629,006.